When wet and dry bulb thermometers record the same temperature, it means

When wet and dry bulb thermometers record the same temperature, it means that the air is saturated. Wet and dry bulb thermometers are used to measure relative humidity, which is the amount of moisture in the air compared to the maximum amount it can hold at a particular temperature. The wet bulb thermometer is wrapped in a wet wick, and the dry bulb thermometer is kept dry. As the water evaporates from the wet wick, it cools the wet bulb thermometer. The greater the difference in temperature between the wet and dry bulbs, the lower the relative humidity. When the air is fully saturated with water vapor, the evaporation of water from the wet bulb is minimized, and the temperatures of the two thermometers become the same. This means that the air cannot hold any more water vapor at that temperature, and the relative humidity is 100%.